Methods and systems for indicating a clamping prediction

ABSTRACT

End effectors with closing mechanisms, and related tools and methods may be particularly beneficial when used for minimally invasive surgery. An example surgical tool comprises a first and second jaw movable between a closed grasped or clamped configuration and an open configuration. The tool further comprises a soft grip mode for grasping the tissue at a first force during which a separation parameter between the jaws is measured, and a therapeutic clamping mode in which the jaws clamp on the body tissue at a force greater than the grasping force. The methods comprise grasping the body tissue between jaws, measuring the separation parameter between the jaws, indicating on a user interface the separation parameter for comparison to a desired separation parameter, and then releasing the body tissue for repositioning or therapeutically clamping the body tissue in response to the separation parameter indication.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of non-provisional applicationSer. No. 13/350,502, filed Jan. 13, 2012, and claims the benefit of U.S.Provisional Patent Application No. 61/443,159, filed Feb. 15, 2011, theentire contents of which are incorporated herein by reference.

The present application is related to U.S. application Ser. No.12/705,418 entitled “Cut and Seal Instrument,” filed on Feb. 12, 2010;U.S. Provisional Application No. 61/260,907, entitled “END EFFECTOR WITHREDUNDANT CLOSING MECHANISMS,” filed on Nov. 13, 2009; U.S. ProvisionalApplication No. 61/260,903, entitled “WRIST ARTICULATION BY LINKEDTENSION MEMBERS,” filed on Nov. 13, 2009; U.S. Provisional ApplicationNo. 61/260,903, entitled “WRIST ARTICULATION BY LINKED TENSION MEMBERS,”filed on Nov. 13, 2009; U.S. Provisional Application No. 61/260,915,entitled “SURGICAL TOOL WITH A TWO DEGREE OF FREEDOM WRIST,” filed onNov. 13, 2009; and U.S. Provisional Application No. 61/260,919, entitled“MOTOR INTERFACE FOR PARALLEL DRIVE SHAFTS WITHIN AN INDEPENDENTLYROTATING MEMBER,” filed on Nov. 13, 2009; each of which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

Minimally invasive surgical techniques are aimed at reducing the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. As a consequence, the average length of ahospital stay for standard surgery may be shortened significantly usingminimally invasive surgical techniques. Also, patient recovery times,patient discomfort, surgical side effects, and time away from work mayalso be reduced with minimally invasive surgery.

A common form of minimally invasive surgery is endoscopy, and a commonform of endoscopy is laparoscopy, which includes minimally invasiveinspection and surgery inside the abdominal cavity. In standardlaparoscopic surgery, a patient's abdomen is insufflated with gas, andcannula sleeves are passed through small (approximately one-half inch orless) incisions to provide entry ports for laparoscopic instruments.

Laparoscopic surgical instruments generally include an endoscope (e.g.,laparoscope) for viewing the surgical field and tools for working at thesurgical site. The working tools are typically similar to those used inconventional (open) surgery, except that the working end or end effectorof each tool is separated from its handle by an extension tube (alsoknown as, e.g., an instrument shaft or a main shaft). The end effectorcan include, for example, a clamp, grasper, scissor, stapler, cauterytool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools throughcannula sleeves to an internal surgical site and manipulates them fromoutside the abdomen. The surgeon views the procedure by means of amonitor that displays an image of the surgical site taken from theendoscope. Similar endoscopic techniques are employed in, for example,arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy,cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems have been recently beendeveloped to increase a surgeon's dexterity when working on an internalsurgical site, as well as to allow a surgeon to operate on a patientfrom a remote location (outside the sterile field). In a telesurgerysystem, the surgeon is often provided with an image of the surgical siteat a control console. While viewing an image of the surgical site on asuitable viewer or display, the surgeon performs the surgical procedureson the patient by manipulating master input or control devices of thecontrol console. Each of the master input devices controls the motion ofa servo-mechanically actuated/articulated surgical instrument. Duringthe surgical procedure, the telesurgical system can provide mechanicalactuation and control of a variety of surgical instruments or toolshaving end effectors that perform various functions for the surgeon, forexample, holding or driving a needle, grasping a blood vessel,dissecting tissue, or the like, in response to manipulation of themaster input devices.

A huge variety of tools have been developed for open surgery, many(though not necessarily all) of which have been successfully modifiedfor minimally invasive surgical procedures. For example, manual clamps,linear cutters, and stapling devices can apply significant therapeuticclamping forces on tissues, which can enhance a variety of surgicalprocedures. Unfortunately, work in connection with the present inventionindicates that adapting open surgical clamping devices (and developingmethods for safely and effectively using them) within minimally invasivesettings may be more challenging than expected. In particular,developing and using surgical clamping jaws capable of generatingdesired clamping force while also providing the desired maneuverabilityfor use within size-restricted minimally invasive surgical access andtreatment sites has proven to be quite difficult. Transferring theadvantages available from surgical staplers, linear cutters, andsurgical clamping tools to robotic surgical settings may involve evenmore challenges, particularly given the different paradigms insurgeon-directed tool movement, tool activation, and physician feedbackpresented by the new telesurgical treatment systems.

Thus, there is believed to be a need for improved methods and systemsfor surgical staplers, linear cutters, and/or other clamping surgicaltools. Such tools may be beneficial in a wide range of surgicalapplications, particularly in minimally invasive and/or robotic surgicalapplications.

BRIEF SUMMARY OF THE INVENTION

Improved systems and methods to facilitate clamping are provided. Theclaimed methods and system can be used to help predict whether clampinga body tissue grasped between jaws at a desired clamping force is likelyto be successful before attempting to clamp. The claimed systems andmethods are particularly useful in surgical applications involvingclamping of a body tissue between two jaws of an end effector. Manysurgical applications involve clamping of a body tissue at a clampingforce sufficient for cutting, sealing and/or stapling of the clampedtissue. Since high force clamping may potentially damage tissues ifclamping fails, the present methods and systems are particularlyadvantageous as they indicate a prediction as to the likelihood ofclamping success before clamping is attempted. While the variousembodiments disclosed herein are primarily described with regard tosurgical applications, these surgical applications are merely exampleapplications, and the disclosed end effectors, tools, and methods can beused in other suitable applications, both inside and outside a humanbody, as well as in non-surgical applications.

In a first aspect, the invention provides a method of indicating whetherclamping of a tissue grasped between a first and second jaw is likely tobe successful. The method includes determining and/or measuring aseparation between two jaws grasping a tissue at a grasping force and,in response to the determination of the separation, outputting on a userinterface an indication of a prediction of whether clamping of thegrasped tissue at a desired clamping force is likely to be successful.In such methods, the clamping force is greater than the grasping forceand, in some embodiments, the clamping force may comprise a firstpredetermined range of forces, each larger than the grasping force. Theindicator of whether clamping success is likely may also comprise anindicator whether clamping success at a desired clamping force and at adesired clamping separation is likely. The desired clamping separationmay comprise a predetermined range of separations. Furthermore, theseparation may be expressed in terms of a separation angle between thefirst and second jaw or a separation distance between jaw members. Inmany embodiments, the desired clamping separation is suitable for firinga staple of a given size through the tissue clamped between the jaws,cutting the grasped tissues, and/or sealing the grasped tissue. Thefirst and second jaws will typically be part of an end effector. Thefirst and second jaw may comprise a first jaw articulable against aportion of the end effector, in which case the portion of the endeffector comprises the second jaw. In certain embodiments, theprediction may be based also on the stiffness of the tissue. Thestiffness of the tissue may be input, if known, or may be estimatedbased on the grasping force and separation or on the rate of change ofseparation as the grasping force is applied. For example, the estimationof stiffness may be based on an empirically derived relationship betweenthese factors and tissue stiffness.

The claimed methods provide an indication of clamping success and/orclamping failure in response to a separation parameter between a firstand second jaw, the first and second jaw having a body tissue graspedtherebetween. In some embodiments, the indication is provided inresponse to the separation parameter and the grasping force. Oneembodiment of the method includes grasping the tissue with the first andsecond jaw, typically in response to a command from a user. The methodfurther includes clamping the tissue between the first and second jaw atthe clamping force, after the system provides an indicator that clampingsuccess is likely. The system clamps the tissue typically in response toa command from a user to clamp the tissue, after the system has providedan indication of whether clamping success or failure is likely. Oneembodiment of the claimed method includes releasing the grasped tissueafter the system has provided an indication of a prediction of clampingfailure. The system releases the grasped tissue typically in response toa command from a user to release the tissue from between the jaws.

In another aspect, the system and methods include a soft grip mode, inwhich the first and second jaw grasp a body tissue at a grasping force,and a clamping mode, wherein the first and second jaw clamp the graspedbody tissue at a clamping force, the clamping force being greater thanthe grasping force. A mechanism coupled with the jaws causes the jaws toclose so as to grasp and/or clamp the body tissue between the first andsecond jaw. The mechanism may be one mechanism coupled with an actuator,such as a motor, or, alternatively, the mechanism may comprise multiplemechanisms for exerting forces of differing magnitudes. The actuator maycomprise an actuator system including one or more actuators. An actuatormaybe any or all of an electric motor, a hydraulic actuator, a pneumaticactuator, and a variable torque output actuator. In embodiments having asoft grip mode and a clamping mode, the system typically switchesbetween modes in response to a user command after the system hasprovided an indication that clamping of the grasped tissue would likelybe successful.

In most embodiments, the separation parameter is measured and/ordetermined by the system during application of a grasping force ortorque. The system may determine/measure the separation between jawmembers from positional data obtained by the robotic system controllingthe jaw members, such as a robotic patient-side manipulator (PSM)system, for example, described in U.S. Patent Application Publication No2007/0005045, the entire contents of which are incorporated herein byreference. Typically, the clamping force is at least twice that of thegrasping force, preferably about 5 to 10 times greater than the graspingforce.

In another aspect of the invention, the indication of the clampingprediction is provided on a user interface. Preferably, the indicationis a visual indicator superimposed over a display providing images ofthe surgical tools during a surgical procedure. In other embodiments,the indication of the clamping prediction may be any of an audio, visualor sensory indicator so as to communicate to the user a prediction ofwhether clamping is likely to be successful. In another aspect of theinvention, the indication of clamping prediction may further include anindication of whether it is safe to initiate a stapling action. Forexample, after a prediction that clamping is likely and clamping hasbeen completed, a timer may be initiated such that once a pre-determinedamount of time has elapsed after successful clamping, an indicator isdisplayed over the display that it is safe to proceed stapling into theclamped tissue. A clamping timing indicator may be advantageous as itmay reduce the amount of clamped tissue over time or reduce the amountof fluid within the tissue so as to reduce bleeding during stapling andhelp achieve hemostasis. The timing indicator may also track elapsedtime of clamping after stapling of the clamped tissue so as to reducebleeding or to aid in achieving hemostasis of the stapled tissue.

In another aspect, the prediction of clamping is provided in response tothe separation parameter between grasped jaws as determined and/ormeasured by the system. In many embodiments, if the measured separationis greater than a threshold or a desired grasping separation parameter,then the prediction is indicative of likely clamping failure, while ifthe grasping separation is equal to or less than the desired graspingseparation parameter, the prediction is indicative of likely clampingsuccess. In some embodiments, the threshold or desired graspingseparation parameter may be based in part on an apparent or estimatedtissue stiffness. The desired separation may comprise either an anglebetween jaws or a distance between jaws, and the separation parametermay be a discrete parameter or a predetermined range of values. For manyapplications, the threshold or desired grasping separation is an angleof about 8 degrees or a distance of about 6 mm between tips of the jawmembers. In one embodiment, a 4 degree angle results in a gap ofapproximately 3 mm between the tips of the jaws. In general, when thetissue is successfully clamped, the gap between jaws is between 1.3 mmto 2 mm, although one of skill in the art would appreciate that thisvalue may vary depending on the application. In embodiments where thedesired separation parameter is a predetermined range, clamping successmay be indicated when the measured separation is within thepredetermined range. For example, a predetermined range of desiredgrasping separation parameters may be from 1 to 10 degrees, preferably 1to 8 degrees, or, in terms of distance, the range of desired graspingseparation parameters from 0.7 mm to 8 mm, preferably 2 to 5 mm.Ideally, the desired target separation is approximately 4 mm. Thedesired separation values or ranges may vary according to any number ofvariables, including but not limited to: a dimension of the first orsecond jaw, a staple length, a staple size, a stapler angle ofarticulation, a thickness of the body tissue, a type of body tissue, acharacteristic of the body tissue the desired clamping force or thedesired clamping separation. In many embodiments, the grasping forcebetween the tips of the jaws will be within a range from about 3 lb-f to10 lb-f, preferably about 5 lb-f, and the clamping force between thetips of the jaws will be within a range from about 30 to 70 lb-f,preferably about 50 lb-f. The grasping force and desired clamping forcemay vary according to any of the above variables or by the type ofsurgical application (e.g. tissue cutting, sealing of tissue, and/orstapling of tissue).

In another aspect, the present invention includes a system forperforming the claimed methods. Ideally, the system comprises a firstand second jaw, a drive system coupled to the jaws, a user interface,and an electronic data processor coupled to the drive system. In manyembodiments, the drive system closes the jaws on tissue at apredetermined grasping force, the electronic data processor measures adistance between the jaws, and based on the measured distance betweenthe jaws, the electronic data processor outputs to the user interface aprediction of success of clamping the tissue between the two jaws at adesired clamping force, wherein the clamping force is within a firstpredetermined range that is larger than the grasping force, and whereinthe clamped jaw separation distance is within a second predeterminedrange. Ideally, the second predetermined range comprises a distancebetween the jaws that is suitable for applying a staple to the tissuebetween the jaws.

The system may also comprise one or more modes of operation. In someembodiments, the system comprises a soft grip mode and a clamping mode.In the soft grip mode, the jaws close or close so as to grasp the bodytissue at the predetermined grasping force. In the clamping mode, thejaws close so as to clamp the body tissue at the clamping force.Typically, the system only provides a prediction of clamping successwhen in the grasping mode, such that a surgeon may grasp tissue in thegrasping mode in preparation for clamping the grasped tissue. Inembodiments having multiple modes, the system may further include acontroller for switching between modes.

The system may include an actuator system coupled with the jaws througha mechanism for effecting movement of the jaws so as to grasp and/orclamp the body tissue. In some embodiments, the mechanism may includecables and a linkage. In many embodiments, the mechanism comprises alead screw and cam. In some embodiments, particularly in embodimentshaving multiple modes, a first mechanism effects grasping of the jaw anda second mechanism effects clamping with the jaws. For example, thefirst mechanism may comprise cables and the second mechanism maycomprise a lead screw. Effecting grasping with cables would be ideal forproviding a fast response with a relatively low force, while a leadscrew would be more suited for provided a higher force despite having alonger response time. The first actuation mechanism can provide a lowforce for grasping the body tissue between jaw members, and the secondactuation mechanism can provide a high clamping force mode. For example,in many embodiments, the maximum clamping force of the movable jawprovided by the second actuation mechanism is larger than a maximumgrasping force provided by the first actuation mechanism.

The first and second actuation mechanisms can employ different forcetransmission mechanisms corresponding with the force requirements forthe low force grasping mode and the high force clamping mode. Forexample, a force used by the first jaw actuation mechanism to move thejaw from the open to the close position can include a linear force, anda force used by the second jaw actuation mechanism to move the jaw fromthe open to the closed position can include a torque. In manyembodiments, the first jaw actuation mechanism for use in the low forcegrasping mode includes a cable-driven mechanism, with the second jawactuation mechanism for use in the high force clamping mode includes aleadscrew-driven mechanism.

Any of the above described methods may be used in the clamping of anymaterial and may be used in application that are non-surgical in nature.For example, the above described methods may be used to indicate to auser a clamping prediction regarding the clamping of a flexiblecompliant material in an industrial process.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive robotic surgery systembeing used to perform a surgery, in accordance with many embodiments.

FIG. 2 is a perspective view of a surgeon's control console for arobotic surgery system, in accordance with many embodiments.

FIG. 3 is a perspective view of a robotic surgery system electronicscart, in accordance with many embodiments.

FIG. 4 diagrammatically illustrates a robotic surgery system, inaccordance with many embodiments.

FIG. 5A is a front view of a patient side cart (surgical robot) of arobotic surgery system, in accordance with many embodiments.

FIG. 5B is a front view of a robotic surgery tool.

FIG. 6A is a perspective view of an end effector having an articulatedjaw, in accordance with many embodiments.

FIG. 6B is a perspective view of the end effector of FIG. 6A (with thearticulated jaw removed to better illustrate leadscrew actuationmechanism components), in accordance with many embodiments.

FIGS. 7A and 7B illustrate components of a leadscrew actuationmechanism, in accordance with many embodiments.

FIG. 8A illustrates components of a cable-driven actuation mechanism, inaccordance with many embodiments.

FIG. 8B is a perspective view of the end effector of FIG. 8A with aportion of the articulated jaw removed to show cable-driven actuationmechanism components disposed behind the articulated jaw used toarticulate the jaw towards a closed configuration, in accordance withmany embodiments.

FIGS. 8C through 8F illustrate opposite side components of thecable-driven actuation mechanism of FIG. 8A used to articulate the jawtowards an open configuration.

FIG. 9A is a perspective view illustrating a cable actuation mechanism,showing a cable used to articulate the jaw towards a closedconfiguration, in accordance with many embodiments.

FIG. 9B is a perspective view illustrating the cable actuation mechanismof FIG. 9A, showing a cable used to articulate the jaw towards an openconfiguration.

FIG. 10 is a cross-sectional view illustrating components of a leadscrewactuation mechanism, in accordance with many embodiments.

FIG. 11 is a simplified diagrammatic illustration of a tool assembly, inaccordance with many embodiments.

FIG. 12 is a simplified diagrammatic illustration of a robotic toolmounted to a robotic tool manipulator, in accordance with manyembodiments.

FIGS. 13A through 13C depict an end effector having a first and secondjaw and illustrate the grasping separation between jaws in a graspingand clamping configuration, in accordance with many embodiments.

FIGS. 14A-14B illustrate an end effector in a grasping configuration, inaccordance with many embodiments.

FIGS. 15A-15B illustrate the user interface assembly having an indicatorof a prediction of tissue clamping, in accordance with many embodiments.

FIGS. 16A-16B illustrate examples of indicators of tissue clampingpredictions, in accordance with many embodiments.

FIGS. 17-19 illustrate methods, in accordance with many embodiments.

FIGS. 20-21 illustrate flow charts utilizing methods in accordance withmany embodiments.

FIGS. 22A-22B illustrate additional examples of indicators in accordancewith many embodiments.

DETAILED DESCRIPTION OF THE INVENTION

Improved systems and methods related to clamping of body tissues areprovided. The present invention relates to providing an indicator ofwhether clamping of grasped tissue is likely before attempting to clampthe tissue. The invention may be used in systems having jaw members forclamping a body tissue, particularly in surgical systems used inminimally invasive surgical applications. Typically, systems utilizingthe claimed methods have jaws that grasp a body tissue at a low forceand subsequently clamp the body tissue at a higher force. Grasping thebody tissue at a low force allows a physician to manipulate and positionthe body tissue between the jaw members without causing damage to thetissue, while clamping at a higher clamping force allows the physicianto perform various procedures, such as tissue cutting and sealing orstapling. While the various embodiments disclosed herein are primarilydescribed with regard to surgical applications, these surgicalapplications are merely example applications, and the disclosed systemsand methods can be used in other suitable applications, both inside andoutside a human body, as well as in non-surgical applications.

In many embodiments, the two jaws comprise an articulated jaw that movestoward a stationary portion of the end effector. In such embodiments,the stationary portion of the end effector comprises the second jaw. Inmany embodiments, the system uses two independent mechanisms toarticulate the jaws of the end effector. A first actuation mechanismprovides a fast response/low force mode that varies the position of thearticulated jaw between a closed (grasped) configuration and an openconfiguration. In many embodiments, the first actuation mechanism isback-drivable. For example, in the low force mode grasping mode thefirst actuation mechanism can be designed to provide 5 lbs of clampingforce between the tips of the first and second jaw. A second actuationmechanism provides a high clamping force mode for clamping the bodytissue between the jaws at the higher clamping force. Often, the secondactuation mechanism is non-back-drivable. The second actuation mechanismconverts a relatively weak force or torque (but with large displacementavailable) to a relatively high torque rotating the jaw of the endeffector. The second actuation mechanism can be designed to provide, forexample, 50 pounds of clamping force between the tips of the clampedjaws.

Typically, in applications using the claimed methods, a surgeon grasps abody tissue at the grasping force between the jaws of the surgical tool,then clamps the body tissue at the higher clamping force. Periodically,the jaws may fail to successfully clamp the tissue at the higherclamping force, which may potentially result in damage to the tissue dueto the high clamping forces. For example, the jaws may clamp on thetissue but the jaw tips may be separated further than desired due toexcess deflection, resulting in potential tissue damage. The jaws mayfail to successfully clamp the tissue for a variety of reasons,including insufficient or excess tissue grasped between the jaws,including interference from an adjacent tissue, such as a bone, orslippage of the tissue from between the jaws. Therefore, it would beadvantageous for a physician to be able to predict when clamping failuremay occur before clamping, thereby avoiding any potential damage to thetissue. The described systems and methods provide an indication to thephysician of a prediction of whether clamping of the body tissue will besuccessful. Clamping may be considered successful when the jaws are inthe clamped position and the distance between the jaws is sufficient forperforming a desired therapy, such as firing a staple through theclamped tissue.

The indication of whether clamping success is more likely than not maybe based, in whole or in part, on the separation between the jaw memberswhile grasping the tissue therebetween. Ideally, the methods includegrasping a tissue at the grasping force, measuring and/or determining aseparation between the jaw members, and providing an indication to thephysician as to whether clamping of the grasped tissue is more likelythan not. The methods may further include measuring or determining therelative stiffness of the grasped tissue. These systems and methods ofthe present invention are particularly beneficial when used in minimallyinvasive surgery applications. Additionally, the indication of clampingsuccess or failure may further include predictions at multiple gripforces (e.g. sequentially higher forces), such that a user may grip witha force that is indicated as likely resulting in successful clamping. Insome embodiments, this feature may be extended to consider thelikelihood of clamping success or failure based on jaw positions duringa continuously increasing grip force. The clamping force may alsoinclude a variable clamping force that is dependent on a relationshipbetween jaw position and gripping force. For example, if the distancebetween jaws is greater than desired, such as may occur when anindication of likely clamping failure is indicated, a higher clampingforce may be applied (e.g. by the user or automatically) and a seconddata point measured to determine an indication of a clamping predictionat the higher clamping force.

Minimally Invasive Robotic Surgery

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 1 is a plan viewillustration of an embodiment of the present invention. FIG. 1illustrates a Minimally Invasive Robotic Surgical (MIRS) system 10,typically used for performing a minimally invasive diagnostic orsurgical procedure on a Patient 12 who is lying down on an Operatingtable 14. The system can include a Surgeon's Console 16 for use by aSurgeon 18 during the procedure. One or more Assistants 20 may alsoparticipate in the procedure. The MIRS system 10 can further include aPatient Side Cart 22 (surgical robot), and an Electronics Cart 24. ThePatient Side Cart 22 can manipulate at least one removably coupled toolassembly 26 (hereinafter simply referred to as a “tool”) through aminimally invasive incision in the body of the Patient 12 while theSurgeon 18 views the surgical site through the Console 16. Tool assembly26 includes end effector 25, the end effector having jaws for graspingand clamping the tissue. An image of the surgical site can be obtainedby an endoscope 28, such as a stereoscopic endoscope, which can bemanipulated by the Patient Side Cart 22 so as to orient the endoscope28. The Electronics Cart 24 can be used to process the images of thesurgical site for subsequent display to the Surgeon 18 through theSurgeon's Console 16. Electronics Cart 24 includes a Processor 27 formeasuring a separation parameter between the jaw members of the tool.The grasping separation parameter may be measured directly orindirectly. The separation may be measured directly by the processorfrom the actual jaw members or from images representing the positions ofthe jaw members, or from various sensors of the system. For example, aHall-effect type sensor can be positioned near the anvil jaw pivot tomeasure the closure angle of the jaws. The Hall-effect type sensor canbe placed in the staple cartridge (or in either jaw of a pair of jaws)and a magnet correspondingly positioned in the anvil jaw (or opposingjaw). The sensor can then sense the magnet's proximity to determine ifthe anvil jaw is sufficiently closed. In another example, a shapesensing optical fiber can be placed in the jaw so that the jaw angle canbe sensed. In some embodiments, at least one jaw may be equipped with adepth gauge and the opposite jaw may be equipped with a sensor tomeasure the depth gauge. For example, the depth gauge may be a smallretractable needle that can be deployed once tissue is grasped tomeasure the separation distance between jaws. The separation may also bemeasured indirectly by calculating the separation from the toolpositional data, such as from positional data, or derivatives thereof,obtained by the PSM. The processor may also provide the indication as towhether clamping is more likely than not in response to the separationparameter. The indication may be determined according to a formula oralgorithm or obtained from a predetermined table of values. The system10 then communicates an indicator of the prediction to the physician onthe Surgeon's Console 16.

FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon'sConsole 16 includes a left eye display 32 and a right eye display 34 forpresenting the Surgeon 18 with a coordinated stereo view of the surgicalsite that enables depth perception. The Console 16 further includes oneor more input control devices 36, which in turn cause the Patient SideCart 22 (shown in FIG. 1) to manipulate one or more tools. The inputcontrol devices 36 will provide the same degrees of freedom as theirassociated tools 26 (shown in FIG. 1) so as to provide the Surgeon withtelepresence, or the perception that the input control devices 36 areintegral with the tools 26 so that the Surgeon has a strong sense ofdirectly controlling the tools 26. To this end, position, force, andtactile feedback sensors (not shown) may be employed to transmitposition, force, and tactile sensations from the tools 26 back to theSurgeon's hands through the input control devices 36.

The Surgeon's Console 16 is usually located in the same room as thepatient so that the Surgeon may directly monitor the procedure, bephysically present if necessary, and speak to an Assistant directlyrather than over the telephone or other communication medium. However,the Surgeon can be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures (i.e., operating from outside the sterile field).

FIG. 3 is a perspective view of the Electronics Cart 24. The ElectronicsCart 24 can be coupled with the endoscope 28 and can include Processor27 to measure and/or determine a separation parameter between jawmembers of the tool and to determine a prediction of clamping success inresponse to the measured separation parameter. Processor 27 may alsoprocess captured images for subsequent display, such as to a Surgeon onthe Surgeon's Console, or on any other suitable display located locallyand/or remotely.

FIG. 4 diagrammatically illustrates a robotic surgery system 50 (such asMIRS system 10 of FIG. 1), in which the Processor 58 and Display 60 aredepicted separately from Electronics Cart 56 and Surgeon's Console 52.As discussed above, a Surgeon's Console 52 (such as Surgeon's Console 16in FIG. 1) can be used by a Surgeon to control a Patient Side Cart(Surgical Robot) 54 (such as Patent Side Cart 22 in FIG. 1) during aminimally invasive procedure. In preparation for clamping of a bodytissue, the Surgeon can command the tool of the Patient Side Cart 54 tograsp a body tissue between jaw members of an end effector. In responseto this command, Processor 58 can measure the separation parameterbetween the jaw members grasping the tissue and subsequently determine aclamping prediction based in whole or in part on the separationparameter. The determination of the clamping prediction may also includethe grasping force, the desired clamping force and the desired distancebetween jaw members in the clamped configuration. The Processor 58 thencommands Display 60 to display an indicator of the prediction to theSurgeon. In response, to the indicator the Surgeon may then safelyproceed with clamping of the body tissue or may abort clamping andreposition the jaws until Display 60 indicates a prediction of clampingsuccess.

FIGS. 5A and 5B show a Patient Side Cart 22 and a surgical tool 62,respectively. The surgical tool 62, one of the surgical tools 26, is anexample of an end effector having a set of jaw members for grasping andclamping a body tissue. The Patient Side Cart 22 shown provides for themanipulation of three surgical tools 26 and an imaging device 28, suchas a stereoscopic endoscope used for the capture of images of the siteof the procedure. Manipulation is provided by robotic mechanisms havinga number of robotic joints. The imaging device 28 and the surgical tools26 can be positioned and manipulated through incisions in the patient sothat a kinematic remote center is maintained at the incision so as tominimize the size of the incision. Images of the surgical site caninclude images of the distal ends of the surgical tools 26 when they arepositioned within the field-of-view of the imaging device 28.

Tissue Grasping and Clamping with Independent Actuation Mechanisms

In many embodiments, two independent actuation mechanisms are used tocontrol the articulation of an articulated jaw of an end effector. Afirst actuation mechanism can be used to provide a fast response/lowforce grasping mode, and a second actuation mechanism can be used toprovide a high clamping force mode, the clamping force being greaterthan the grasping force. In many embodiments, the first actuationmechanism used to provide the fast response/low force articulation modeis back-drivable. In many embodiments, the second actuation mechanismused to provide the high clamping force articulation mode isnon-back-drivable. Using independent actuation mechanisms may bebeneficial in some surgical applications, for example, electrocauterysealing, stapling, etc., that may require multiple low force jawplacement clampings before a high force jaw clamping is used to carryout the surgical tool's task.

In many embodiments, actuation of the jaws in the fast response/lowforce grasping mode is provided by a cable actuation mechanism thatincludes a pair of pull cables. In many embodiments, a pulling motion ofa first cable of the pair articulates the articulated jaw towards aclosed (grasped) configuration and a pulling motion of a second cable ofthe pair articulates the articulated jaw towards an open (ungrasped)configuration. In many embodiments, the cable actuation mechanism isback-drivable.

In many embodiments, actuation of the jaws in the high clamping forcemode is provided by a leadscrew actuation mechanism that includes aleadscrew driven cam. The driven cam interfaces with a mating camsurface on the articulated jaw so as to hold the articulated jaw in aclosed (clamped) configuration when the leadscrew driven cam is at afirst end of its range of motion. In addition, the driven cam does notconstrain motion of the articulated jaw when the leadscrew driven cam isat a second end (opposite end) of its range of motion. In other words,the mating cam surfaces are arranged such that motion of the leadscrewdriven cam in one direction will cause the articulated jaw to close, andmotion of the leadscrew driven cam in the reverse direction will allow(but not force) the articulated jaw to open to a limit provided by thecam surfaces. Often, the leadscrew actuation mechanism isnon-back-drivable. In many embodiments, the position of the jaw membersof the end effector can be determined by the position of the cableactuation mechanism, or if driven by a leadscrew, the position of theleadscrew.

FIG. 6A is a perspective view of an end effector 70 having a jaw 72articulated by two independent actuation mechanisms, in accordance withmany embodiments. The end effector 70 includes an end effector base 74,the articulated jaw 72, and a detachable stationary jaw 76. The endeffector 70 is actuated via a first drive shaft 78, a second drive shaft80, and two actuation cables (not shown). The first drive shaft 78rotates a leadscrew 82 of a leadscrew actuation mechanism. The seconddrive shaft 80 rotates another leadscrew (not shown) of the detachablestationary jaw/staple cartridge reload 76.

In many embodiments, the first drive shaft 78 and/or the second driveshaft 80 are driven by drive features located in a proximal tool chassisto which the end effector 70 is coupled with via an instrument shaft. Inmany embodiments, the proximal tool chassis is configured to bereleasably mountable to a robotic tool manipulator. In many embodiments,the first drive shaft 78 and the second drive shaft 80 are actuated viarespective drive features located in the proximal tool chassis. In manyembodiments, such drive features are driven by an actuator or motorsystem that is located in the proximal tool chassis.

FIG. 6B is a perspective view of the end effector 70 of FIG. 6A (withthe articulated jaw 72 removed to better illustrate components of theleadscrew actuation mechanism), in accordance with many embodiments. Theleadscrew 82 is mounted for rotation relative to the end effector base74. A leadscrew driven cam 84 is coupled with the leadscrew 82 so thatselective rotation of the leadscrew 82 can be used to selectivelytranslate the leadscrew driven cam 84 along a cam slot 86 in the endeffector base 74. The end effector 70 includes a pivot pin 88 that isused to rotationally couple the articulated jaw 72 with the end effectorbase 74.

FIGS. 7A through 10 illustrate the actuation mechanisms by which an endeffector grasps a body tissue between its jaws in the low force graspingmode and clamps the body tissue grasped between its jaws with a higherclamping force.

FIGS. 7A and 7B illustrate the leadscrew actuation mechanism of FIGS. 6Aand 6B. The leadscrew 82 has a distal journal surface 96 and a proximaljournal surface that interfaces with a proximal bearing 98. In manyembodiments, the distal journal surface 96 is received within acylindrical receptacle located at the distal end of the cam slot 86.Such a distal support for the leadscrew 82 can be configured to keep theleadscrew 82 from swinging excessively, and with relatively largeclearance(s) between the distal journal surface 96 and the cylindricalreceptacle. The proximal bearing 98 is supported by the end effectorbase 74 so as to support the proximal end of the leadscrew 82. Theproximal bearing 98 can be a ball bearing, which may help to reducefriction and wear. A distal bearing (not shown) can be supported by theend effector base 74 so as to support the distal end of the leadscrew82, and the distal bearing can be a ball bearing. The leadscrew drivencam 84 includes a threaded bore configured to mate with the externalthreads of the leadscrew 82. The leadscrew driven cam 84 includes topand bottom surfaces configured to interact with corresponding top andbottom surfaces of the cam slot 86. The interaction between leadscrewdriven cam 84 and the cam slot 86 prevents the leadscrew driven cam 84from rotating relative to the cam slot 86, which causes the leadscrewdriven cam 84 to translate along the cam slot 86 in response to rotationof the leadscrew.

The articulated jaw 72 includes mating cam surfaces 94 that areconfigured so that the position of the leadscrew driven cam 84 along thecam slot 86 determines the extent to which the rotational motion of thearticulated jaw 72 around the pivot pin 88 is constrained by theleadscrew driven cam 84. The articulated jaw 72 includes a firstproximal side 100 and a second proximal side 102 that are separated by acentral slot. The first and second proximal sides are disposed onopposing sides of the end effector base 74 when the articulated jaw 72is coupled with the end effector base 74 via the pivot pin 88. Each ofthe first and second proximal sides 100, 102 includes a recessed areadefining a mating cam surface 94 and providing clearance between theleadscrew driven cam 84 and the proximal sides 100, 102. When theleadscrew driven cam 84 is positioned at or near the proximal end of thecam slot 86 (near its position illustrated in FIGS. 7A and 7B), contactbetween the leadscrew driven cam 84 and the mating cam surfaces 94 ofthe articulated jaw 72 hold the articulated jaw in a clampedconfiguration. When the leadscrew driven cam 84 is positioned at thedistal end of the cam slot 86, the rotational position of thearticulated jaw around the pivot pin 88 is unconstrained by theleadscrew driven cam 84 for a range of rotational positions between aclamped configuration (where there is a gap between the leadscrew drivencam 84 and the mating cam surfaces 94 of the articulated jaw 72) and anopen configuration (where there may or may not be a gap between theleadscrew driven cam 84 and the mating cam surfaces 94 of thearticulated jaw 72). For positions of the leadscrew driven cam 84 inbetween the proximal and distal ends of the cam slot 86, the range ofunconstrained motion can vary according to the cam surfaces used.

The use of a recess in each of the proximal sides 100, 102 to define themating cam surfaces 94 of the articulated jaw 72 provides a number ofbenefits. For example, the use of recesses as opposed to traverse slotsthat extend through the proximal sides provides a continuous outsidesurface to the proximal sides 100, 102 of the articulated jaw, which isless likely to snag on patient tissue than would a traverse slotopening. The absence of traverse slots also helps to stiffen theproximal sides 100, 102 as compared to proximal sides with traverseslots, and therefore provides increased clamping stiffness. Suchproximal sides 100, 102 may have increased stiffness in two planes,which may help maintain alignment of the articulated jaw 72 in thepresences of external forces. Such increased stiffness in two planes maybe beneficial in some surgical applications, for example, in tissuestapling where it is beneficial to maintain alignment between thestaples and anvil pockets that form the staples. Further, the use ofrecesses instead of traverse slots also provides an actuation mechanismthat is less likely to be jammed by extraneous material as compared toone having proximal sides with open traverse slots.

The leadscrew actuation mechanism can be configured to provide a desiredclamping force between the articulated jaw and an opposing jaw of theend effector. For example, in many embodiments, the leadscrew actuationmechanism is configured to provide at least 20 lbs of clamping force atthe tip of the articulated jaw 72 (approximately 2 inches from the pivotpin 88). In many embodiments, the leadscrew actuation mechanism isconfigured to provide at least 50 lbs of clamping force at the tip ofthe articulated jaw 72. In many embodiments, to produce 50 lbs ofclamping force at the tip of the articulated jaw 72, the input torque tothe leadscrew 82 is approximately 0.1 Newton meter and the leadscrew 82has approximately 30 turns.

The leadscrew actuation mechanism can be fabricated using availablematerials and components. For example, many components of the leadscrewactuation mechanism can be fabricated from an available stainlesssteel(s). The leadscrew driven cam 84 can be coated (e.g., TiN) toreduce friction against the surfaces it rubs against (e.g., leadscrew82; end effector base 74; proximal sides 100, 102 of the articulated jaw72). Stranded cables can be used to drive the first actuation mechanism.

FIGS. 8A through 8F illustrate components of a cable actuation mechanism110, in accordance with many embodiments. As described above, theleadscrew driven cam 84 can be positioned at the distal end of the camslot 86 (i.e., near the pivot pin 88). For such a distal position of theleadscrew driven cam 84, as discussed above, the rotational position ofthe articulated jaw 72 about the pivot pin 88 is unconstrained for arange of rotational positions of the articulated jaw 72. Accordingly,the rotational position of the articulated jaw 72 about the pivot pin 88can be controlled by the cable actuation mechanism 110. The cableactuation mechanism 110 is operable to vary the rotational position ofthe articulated jaw between the closed configuration and the openconfiguration. The cable actuation mechanism 110 includes a pair of pullcables 112, 114. The cable actuation mechanism 110 also includes a firstlinkage 116 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the closed configuration, and an analogous secondlinkage 118 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the open configuration. The first linkage 116(shown in FIGS. 8A and 8B) includes a rotary link 120 that is mountedfor rotation relative to the end effector base 74 via a pivot pin 122. Aconnecting link 124 couples the rotary link 120 to the articulated jaw72 via a pivot pin 126 and a pivot pin 128. The first linkage 116 isarticulated via a pulling motion of the pull cable 112. In operation, apulling motion of the pull cable 112 rotates the rotary link 120 in aclockwise direction about the pivot pin 122. The resulting motion of theconnecting link 124 rotates the articulated jaw 72 in acounter-clockwise direction about the pivot pin 88 towards the closedconfiguration.

The second linkage 118 (shown in FIGS. 8C through 8F) of the cableactuation mechanism 110 includes analogous components to the firstlinkage 116, for example, a rotary link 130 mounted for rotationrelative to the end effector base 74 via a pivot pin 132, and aconnecting link 134 that couples the rotary link 130 to the articulatedjaw 72 via two pivot pins 136, 138. The second linkage 118 isarticulated via a pulling motion of the pull cable 114. The secondlinkage 118 is configured such that a pulling motion of the pull cable114 rotates the articulated jaw 72 about the pivot pin 88 towards theopen configuration. In many embodiments, the pivot pin 136 between theconnecting link 134 and the rotary link 130 of the second linkage 118 is180 degrees out of phase with the pivot pin 126 between the connectinglink 124 and the rotary link 120 of the first linkage 116. Coordinatedpulling and extension of the pull cables 112, 114 of the cable actuationmechanism 110 is used to articulate the articulated jaw 72 between theopen and closed configurations. In order to best provide equal andopposite cable motion (and thereby maintain cable tension in acapstan-driven system described below), a common rotational axis for thepivot pins 122, 132 is configured to lie on a plane that contains therotational axes for pivot pins 128, 138 when the articulated jaw 72 isclosed (or nearly closed) and again when the when the articulated jaw 72is open (or nearly open). The connecting links 124, 134 are assembledsymmetrically opposite about this same plane for the first and secondlinkages 116, 118. The distance between the pivot pins 122, 126 andbetween the pivot pins 132, 136 is the same for both the first andsecond linkages 116, 118, and the distance between the pivot pins 126,128 and between the pivot pins 136, 138 is the same for both the firstand second linkages 116, 118.

FIGS. 9A and 9B illustrate an articulation of the articulated jaw 72 viaanother cable actuation mechanism 140, in accordance with manyembodiments. In embodiment 140 of the cable actuation mechanism, a firstpull cable 142 and a second pull cable 144 are directly coupled with theproximal end of the articulated jaw 72. The first pull cable 142 wrapsaround a first pulley 146 so that a pulling motion of the first pullcable 142 rotates the articulated jaw 72 about the pivot pin 88 towardsthe clamped configuration. The second pull cable 144 wraps around asecond pulley 148 so that a pulling motion of the second pull cable 144rotates the articulated jaw 72 about the pivot pin 88 towards the openconfiguration. Accordingly, coordinated pulling and extension of thefirst and second pull cables of the cable actuation mechanism 140 isused to articulate the articulated jaw 72 between the open and clampedconfigurations. In order to best provide equal and opposite cable motion(and thereby maintain cable tension in the capstan-driven systemdescribed below), the radius of the arc prescribed by cable 142 aboutthe pivot 88 is substantially the same as the radius prescribed by cable144 about the pivot 88.

In many embodiments, the cable (i.e., low force) actuation mechanismcomprises a pair of pull cables that are actuated via an actuationfeature disposed in a proximal tool chassis. The proximal tool chassiscan be configured to be releasably mountable to a robotic toolmanipulator having a drive mechanism that operatively couples with theactuation feature. For example, the pair of pull cables can be wrappedaround a capstan located in the proximal tool chassis. The capstan canbe operatively coupled with a capstan drive servo motor of the robotictool manipulator when the proximal tool chassis is mounted to therobotic tool manipulator. Selective rotation of the capstan drive motorcan be used to produce a corresponding rotation of the capstan. Rotationof the capstan can be used to produce a coordinated extension andretraction of the pull cables. As discussed above, coordinated actuationof the pull cables can be used to produce a corresponding articulationof the articulated jaw of the end effector.

In many embodiments, the fast response/low force mode is provided by acable actuation mechanism that is back-drivable. For example, anexternal force applied to the articulated jaw can be used to rotate thearticulated jaw towards the clamped configuration and back-drive thecable actuation mechanism. With a cable actuation mechanism thatcomprises a pair of pull cables wrapped around a capstan, an externalforce that rotates the articulated jaw towards the closed configurationproduces an increase in tension in one of the pull cables and a decreasein tension in the other pull cable, thereby causing the capstan torotate in response. As is known, such a cable driven system can beconfigured to have sufficient efficiency for back-drivability. Likewise,an external force applied to the articulated jaw can be used to rotatethe articulated jaw towards the open configuration and back-drive thecable actuation mechanism. As discussed above, a back-drivable fastresponse/low force actuation mechanism provides a number of benefits.

Alternate mechanisms can be used to provide a fast response/low forcearticulation mode. For example, an actuation mechanism comprisingpush/pull rods can be used.

FIG. 10 is a cross-sectional view illustrating components of the abovediscussed leadscrew actuation mechanism. The illustrated componentsinclude the leadscrew 82, the leadscrew driven cam 84, the cam slot 86in the end effector base 74, the distal journal surface 96, thecylindrical receptacle 154 in the end effector base, and the proximalbearing 98 supported by the end effector base 74.

FIG. 11 is a simplified perspective view diagrammatic illustration of atool assembly 170, in accordance with many embodiments. The toolassembly 170 includes a proximal actuation mechanism 172, an elongateshaft 174 having a proximal end and a distal end, a tool body 176disposed at the distal end of the shaft, a jaw 178 movable relative tothe tool body 176 between a clamped configuration and an openconfiguration, a first actuation mechanism coupled with the jaw, and asecond actuation mechanism coupled with the jaw. The first actuationmechanism is operable to vary the position of the jaw relative to thetool body between the clamped configuration and the open configuration.The second actuation mechanism has a first configuration where the jawis held in the clamped configuration and a second configuration wherethe position of the jaw relative to the tool body is unconstrained bythe second actuation mechanism. The first actuation mechanism isoperatively coupled with the proximal actuation mechanism. In manyembodiments, the first actuation mechanism comprises a pair of pullcables that are actuated by the proximal actuation mechanism. The secondactuation mechanism is operatively coupled with the proximal actuationmechanism. In many embodiments, the second actuation mechanism includesa leadscrew driven cam located in the tool body that is driven by theproximal actuation mechanism via a drive shaft extending through theelongate shaft 174 from the proximal actuation mechanism. Although toolassembly 170 has been described as having a first and second actuationmechanism, in some embodiments tool assembly 170 could be constructedwith a single actuation mechanism driven with a variable force motorsuch that the tool could both grasp body tissue with a relatively lowforce and subsequently clamp the grasped body tissue with a higherclamping force with the single actuation mechanism.

The tool assembly 170 can be configured for use in a variety ofapplications. For example, the tool assembly 170 can be configured as ahand held device with manual and/or automated actuation used in theproximal actuation mechanism. The tool assembly 170 can also beconfigured for use in surgical applications, for example, electrocauterysealing, stapling, etc. The tool assembly 170 can have applicationsbeyond minimally invasive robotic surgery, for example, non-roboticminimally invasive surgery, non-minimally invasive robotic surgery,non-robotic non-minimally invasive surgery, as well as otherapplications where the use of the disclosed redundant jaw actuationwould be beneficial.

Redundant jaw actuation can be used to articulate a jaw of a robotictool end effector. For example, FIG. 12 schematically illustrates arobotic tool 180 employing redundant jaw actuation. The robotic tool 180includes a proximal tool chassis 182, a drive motor 184, an instrumentshaft 186, a distal end effector 188, a first actuation mechanismportion 190, and a second actuation mechanism 192. The distal endeffector 188 comprises an articulated jaw 194. The proximal tool chassis182 is releasably mountable to a robotic tool manipulator 196 having afirst drive 198, and a first actuation mechanism portion 200 thatoperatively couples with the first actuation mechanism portion 190 ofthe robotic tool 180 when the proximal tool chassis 182 is mounted tothe robotic tool manipulator 196. The instrument shaft 186 has aproximal end adjacent the tool chassis 182, and a distal end adjacentthe end effector 188. The first actuation mechanism (comprising portion200 and portion 190) couples the first drive 198 to the articulated jaw194 when the tool chassis 182 is mounted to the tool manipulator 196 soas to articulate the end effector 188 between an open configuration anda closed configuration. The second actuation mechanism 192 couples thedrive motor 184 to the articulated jaw 194 so as to articulate the endeffector into the clamped/closed configuration from the openconfiguration. The first actuation mechanism can be a cable actuationmechanism, for example, an above discussed cable actuation mechanismthat provides the fast response/low force mode. In many embodiments, thefirst actuation mechanism is back-drivable. The second actuationmechanism can include a drive shaft that couples the drive motor 184with a leadscrew actuation mechanism, for example, an above discussedleadscrew actuation mechanism that provides the high clamping forcemode. In many embodiments, the second actuation mechanism isnon-back-drivable. In both modes, the position of the jaw members isobtained by the PSM coupled with end effector 188. From the positionaldata obtained by the PSM during grasping of a body tissue with the endeffector, Processor 191 can determine the separation parameter andassociated prediction of clamping success with the end effector at theclamping force.

FIGS. 13A-13C illustrate an example of the separation parameter endeffector 188 and depicts end effector 188 in both the grasping andclamping positions. FIG. 13A depicts the jaws of end effector 188wherein the separation parameter (s) is a distance between the tips ofthe jaw members or may be an angle between jaw members. FIG. 13Billustrates end effector 188 grasping a body tissue (T) between jawmembers at grasping force (Fg). In this embodiment, the system measuresthe separation parameter when the body tissue T is grasped between jawmembers at known force Fg. In response, the system provides anindication on the user interface as to whether clamping of the graspedbody tissue T at a higher clamping force (Fc) is more likely than not.The indication of the likelihood of clamping success may be based, inwhole or in part, on the separation parameter, but may also be based onadditional factors, including but not limited to: a type of body tissue(T) (e.g. bowel, stomach), a thickness of the body tissue, a desiredclamping force Fc, and a desired separation between jaw members in thefully clamped state. For example, in one embodiment, the claimed systemmay provide an indication as to the likelihood of clamping the graspedtissue at the clamping force Fc in response to the grasping separationparameter being less than a threshold or desired grasping separation.Alternatively, if the measured separation is greater than thepredetermined separation parameter, then the system may provide anindication to the user that clamping may likely not be successful. Thepredetermined separation parameter may vary according to any of theabove stated additional factors. FIG. 13C illustrates end effector 188having successfully clamped body tissue T between jaw members atclamping force Fc, the clamping force being within a desired range offorces greater than grasping force Fg.

FIGS. 14A-14B illustrate two examples of end effector 188 having graspedbody tissue T at grasping force Fg. FIG. 14A depicts an example whereinthe actual separation (s_(a)) between the jaws of end effector 188 whengrasping the tissue is less than the predetermined grasping separationor target separation (s_(t)) as determined for a clamping prediction ata given desired clamping force Fc and/or desired clamping separation. Inthis example, the system would predict successful clamping and providean indication of the prediction to the Surgeon on the user interface.FIG. 14B depicts an example wherein the body tissue is positioned suchthat clamping may not be successful due to tissue slippage orinsufficient tissue between the jaws of the end effector. In thisexample, the actual measured separation (s_(a)) between the jaws of endeffector 188 is greater than the predetermined separation or targetseparation (s_(t)) as determined for a clamping prediction at a givenclamping force Fc and/or clamping separation. In this embodiment, thesystem would predict that clamping would likely not be successful andprovide an indication of the prediction to the Surgeon on the userinterface. After providing an indication that clamping would likely notbe successful, the system may prevent the Surgeon from clamping, absentadditional input from the user.

FIGS. 15A-15B illustrate the indication on the user interface Display 60of System 10 as to whether clamping of grasped tissue would likely besuccessful. Typically, the user interface Display 60 images and/orvisual representations of the surgical tool end effectors during thesurgery in addition to the indicators of clamping predictions. Theindication of clamping prediction may be superimposed over the images onthe user interface display during the surgical procedure so as toseamlessly incorporate the feature into the surgical procedure.Preferably, the clamping prediction indicators only appear when theSurgeon effects grasping of the tissue in preparation for clamping. Theindication of clamping prediction facilitates successful clamping ofbody tissue by the Surgeon during surgery, while minimizing thepotential for tissue damage from unsuccessful clamping. FIG. 15A depictsDisplay 60 with the clamping prediction indicator 250 superimposed onthe lower right area of the screen, wherein the indicator predictsclamping is more likely than not. FIG. 15B depicts Display 60 with theclamping prediction indicator 250 superimposed on the lower right areaof the screen, wherein the indicator indicates a prediction thatclamping will likely not be successful. Often, the Surgeon will not beable to visualize the entire surgical tool with an endoscope due tointerference from the body tissue, or the Surgeon may be viewing visualrepresentations of the tools. In FIGS. 15A-15B, the graphicalrepresentations of the jaws of end effector 189 on Display 160 areexaggerated and, generally, the Surgeon may not be able to ascertainwhether clamping will be successful solely from viewing the images ofthe surgical tools on Display 60.

FIG. 16A-16B illustrate additional examples of the clamping predictionindicator 250. FIG. 16A depicts an example of an indicator wherein theclamping prediction is a gradient of likely clamping success. The systemand methods may determine a prediction within the gradient based onvarious factors, including but not limited to: the difference betweenthe actual separation and the predetermined target separation betweenjaws grasping the tissue, a type of tissue, a thickness of the tissue,or the desired clamping force and/or clamping separation. For example,the predetermined separation when the jaws are grasped tissue may be arange of acceptable grasping separations, and the further outside therange of predetermined grasping separation the actual measured graspingseparation is, the less likely clamping success will be. For example, inone embodiment, if actual measured separation is within 0-2 degrees,then the system will display an indicator of 99% likelihood of clampingsuccess. As the measured separation increases from 2-8 degrees, thelikelihood decreases in a monotonically decreasing relationship, such asfrom 99% down to 10%. FIG. 16B depicts an embodiment having an indicatorwhich toggles between two settings, a predicted clamping success settingand a predicted clamping failure setting. In this example, the indicatoris simply a light that when lit indicates that clamping is more likelythan not, and when dark indicates that clamping success is not likely.

FIGS. 17-19 graphically illustrate embodiments of the claimed methods.FIG. 17 is a simplified representation of exemplary method 300. Method300 includes a step 302 of measuring a separation between two jawsgrasping a tissue at a known grasping force and a step 304 of indicatingon a user interface that clamping success or failure is likely whenclamping the grasped tissue between the two jaws at a higher clampingforce. FIG. 18 is a simplified representation of a method 310 whichfurther includes the step 312 of grasping a body tissue between jaws ata grasping force by the system typically in response to a command from auser and a step 318 of clamping the body tissue between the jaws at theclamping force in response to a command from a user to clamp the tissueafter the system has measured the separation between jaws and providedan indication of predicted clamping success in steps 314 and 316,respectively. FIG. 19 is a simplified representation of a method 320which further includes the step 334 repositioning the jaws on the bodytissue in response to a command from a user to reposition the jaws afterthe system has performed step 332 of providing an indication thatclamping success is likely.

FIGS. 20-21 depict flowcharts illustrating embodiments of the claimedmethods. FIG. 20 is a flow chart showing an embodiment of the claimedmethod wherein the system reads the separation (jaw angle) from the PSMafter the body tissue has been grasped between the jaws (MTM gripsclosed on tissue). If the separation (angle) is less than thepredetermined separation (threshold angle), then the system indicates tothe user that clamping is likely to succeed. If the separation (angle)is not less than the predetermined separation (threshold), then thesystem indicates to the user that clamping is unlikely to succeed. Ifthe user provides an input to the system to clamp (blue pedal pressed),then the system proceeds with clamping of the tissue grasped within thejaws. FIG. 20 is a flow chart showing an embodiment of the claimedmethod incorporated into a surgical system for clamping and sealing abody tissue by firing a staple into the clamped tissue. In FIGS. 20-21,the systems may require user input, such as pressing a blue or yellowpedal, before performing a selected action.

FIGS. 22A-22B illustrate an indication on the user interface Display 60of System 10 as to whether it is advisable to proceed with stapling ofthe clamped tissue. The indication may be solely an indicator of whetherit is safe to proceed with stapling or may further include a timer forshowing an elapsed time (or alternately a countdown) after clamping ofthe tissue with end effector 189. The indicator 250 may be similar tothe indicator illustrated in FIGS. 15A-15B, however, may further includethe above described features. The stapling safety indicator and/or timerfeatures are advantageous as allowing the clamped tissue to remainclamped for a specified amount of time before stapling may slightlyreduce the thickness of tissue being clamped by squeezing out fluid(e.g., blood) within the tissue to be stapled. Reducing the amount offluid in the clamped tissue is advantageous as it may reduce thelikelihood of bleeding from the staple insertion points during and afterstapling. Typically, when tissue is properly clamped between the jaws ofthe end effector 189, a finite amount of time is required for theclamped tissue to compress (e.g., fluids squish out from the tissuebetween the jaws) before stapling is initiated. The amount of timeneeded for sufficient compression and reduction of fluid may varyaccording to the type and size of staple, the type of stapler and/orclamp, as well as the type and thickness of the tissue being clamped.For example, in performing staple of a bowel tissue, it has been shownthat waiting for at least one minute after clamping before stapling ofthe tissue significantly reduces the amount of bleeding resulting fromstapling; however one of skill in the art would appreciate that theduration of time to wait could be less than one minute or greater thanone minute, often depending on the procedure and tissue to be stapled.Additionally, maintaining clamping of the tissue after stapling mayfurther reduce bleeding from the stapled tissue and promote hemostasis.The indicator may provide an elapsed time (or a countdown from arecommended wait time) so that the system and/or the Surgeon canrecognize that the required time has elapsed and that it is safe toproceed with stapling. In other embodiments, an additional indicatormessage (e.g., “wait to staple,” “proceed with stapling”) may aid inindicating to a surgeon that it is advisable to proceed with stapling ofthe clamped tissue. Such an indication may include, but is not limitedto, a change in color in the time indicator display, a change inbackground color on the display, a light, a sound, or any otherindicator suitable for communicating stapling safety and/or clampingduration to the Surgeon. The recommended clamping wait times may bepre-set in the system according to any of the variables of theprocedure, or alternatively, may be input by the Surgeon.

In FIG. 22A of the above described embodiment, the Surgeon hassuccessfully clamped the tissue with the jaws of end effector 189, arepresentation of which is visible on the Display 60. Indicator 250 inthe lower right corner of the Display 60 indicates that clamping hasbeen completed and further instructs the surgeon with the message “Waitto Staple,” while a timer indicates the time that has elapsed sincesuccessful clamping of the tissue. In this embodiment, the recommendedtime to wait before stapling is one minute. As shown in FIG. 22B, afterone minute has elapsed, the indicator 250 displays the elapsed time withthe message “Proceed to Staple,” after which the surgeon may proceedwith stapling of the clamped tissue. In an alternate embodiment, thetimer may restart after stapling of the tissue so as to allow a Surgeonto maintain clamping on the stapled tissue.

It is understood that the examples and embodiments described herein arefor illustrative purposes and that various modifications or changes inlight thereof will be suggested to persons skilled in the art and are tobe included within the spirit and purview of this application and thescope of the appended claims. Numerous different combinations arepossible, and such combinations are considered to be part of the presentinvention.

The invention claimed is:
 1. A method comprising: measuring a graspingparameter between two jaws grasping a material with a grasping force;and outputting an indication in response to the measured graspingparameter, wherein the indication indicates a predicted success orfailure of clamping the grasped material between the two jaws at adesired clamping force, wherein the desired clamping force is in a rangeof clamping forces greater than the grasping force, the indicationcomprising an indicator.
 2. The method of claim 1, wherein the indicatorcomprises a sensory indicator.
 3. The method of claim 2, wherein thesensory indicator comprises an audible sound, a visual indicator, ahaptic response, or any combination thereof.
 4. The method of claim 3,wherein the visual indicator comprises a graphical representation on auser interface display.
 5. The method of claim 1, wherein the methodfurther comprises: determining successful clamping of the material; andoutputting an indicator of the successful clamping of the material. 6.The method of claim 5, wherein the method further comprises after apre-determined period of time elapses after the successful clamping,outputting an indicator that it is safe to proceed with stapling of theclamped material.
 7. The method of claim 1, wherein the method isnon-surgical in nature and the material comprises a compliant material.8. The method of claim 1, further comprising applying the grasping forcein response to a measurement grasping force command.
 9. The method ofclaim 1, wherein the indication is of predicted success and is output inresponse to a determination that a predicted clamped jaw separation iswithin a desired range of clamped jaw separations when clamping thegrasped material between the two jaws at the desired clamping force. 10.The method of claim 9, wherein the desired range of clamped jawseparations is determined based on a dimension of a staple or fastenerto be used in stapling or fastening the clamped material.
 11. The methodof claim 9, wherein the desired range of clamped jaw separationscomprises a distance between the jaws that is suitable for applying astaple to the material between the jaws.
 12. The method of claim 1,wherein the material comprises living tissue.
 13. The method of claim12, the method further comprising: therapeutically clamping the tissuebetween the jaws at the desired clamping force in response to a usercommand to clamp and after providing the indication of predictedsuccess, or; releasing the tissue from between the jaws after providingthe indication of predicted failure in response to a user command. 14.The method of claim 12: wherein the grasping occurs in a soft griptissue manipulation mode and the clamping occurs in a therapeuticclamping mode; the method further comprising: switching from the softgrip tissue manipulation mode to the therapeutic clamping mode.
 15. Themethod of claim 14, wherein switching from the soft grip tissuemanipulation mode to the therapeutic clamping mode occurs in response toa user input command to clamp the tissue.
 16. The method of claim 1,wherein: grasping the material comprises driving the jaws with agrasping torque applied by an actuator system; and the graspingparameter is measured during application of the grasping torque.
 17. Themethod of claim 1, wherein the parameter comprises an angle between thejaws or a distance between the jaws.
 18. The method of claim 17, whereinthe angle between the jaws is within a range from 1 degree to about 10degrees.
 19. The method of claim 1, wherein the desired clamping forceis at least twice the grasping force.
 20. The method of claim 19,wherein the desired clamping force is between 5 to 10 times the graspingforce.
 21. The method of claim 1, wherein: the indication comprisespredicted clamping failure when the measured grasping parameter isgreater than a desired grasping separation; and the indication comprisespredicted clamping success when the measured grasping parameter is equalto or less than the desired grasping parameter.
 22. The method of claim1, wherein: each of the jaws has a distal tip; and the graspingparameter corresponds to a separation distance between the distal tipsof the jaws.
 23. The method of claim 22, wherein the separation distanceis within a range of about 0.7 mm to 8 mm.
 24. The method of claim 22,wherein the separation distance is about 4 mm.
 25. The method of claim22, wherein the grasping force corresponds to a tip force between thedistal tips of the jaws within a range from about 3 lb-f to 10 lb-f. 26.The method of claim 22, wherein the desired clamping force correspondsto a tip force between the distal tips of the jaws within a range fromabout 30 lb-f to 70 lb-f.
 27. The method of claim 1, further comprisingdetermining the desired grasping parameter in response to one or moreclamping parameters, the one or more clamping parameters including anyor all of a dimension of the jaws, a texture of a clamping surface onthe jaws, a dimension of a staple, and a characteristic of the materialbeing clamped.
 28. The method of claim 27, wherein the characteristic ofthe material comprises any of a type of tissue, a thickness of tissue, astiffness of tissue or any combination thereof.
 29. The method of claim1, further comprising: automatically repositioning the jaws relative tothe material, in response to the indication being of predicted failure;after the repositioning of the jaws, automatically grasping with thejaws at the grasping force while measuring a second grasping separationbetween the jaws; and outputting a second indication that indicates asecond predicted success or failure of clamping the grasped materialbetween the repositioned jaws at the desired clamping force in responseto the measured second grasping separation between the repositionedjaws.
 30. The method of claim 1, wherein the grasping and/or desiredclamping force varies according to any of: a jaw dimension, a thicknessof the material, a type of the material, a characteristic of thematerial, a desired clamping separation, a type of application, or anycombination thereof.
 31. The method of claim 30, wherein the type ofapplication comprises stapling of the material such that the graspingand/or desired clamping force varies according to any of: a staplelength, a staple size, a stapler angle of articulation, or anycombination thereof.
 32. The method of claim 30, wherein the materialcomprises a living tissue, and the type of application is tissuecutting, tissue sealing, or tissue stapling.
 33. The method of claim 1,wherein grasping the material comprises driving the jaws with a firstactuation mechanism, and clamping the material comprises driving thejaws with a second actuation mechanism different from the firstactuation mechanism.
 34. The method of claim 33, wherein first actuationmechanism comprises a cable-driven mechanism and the second actuationmechanism comprises a leadscrew-driven mechanism.
 35. The method ofclaim 1 wherein measuring a grasping parameter and outputting anindication in response to the measured grasping parameter comprisesmeasuring multiple grasping parameters at sequentially increasinggrasping forces and outputting multiple indications in response to thecorresponding multiple measured grasping parameters.